Guess what? You don’t know this classic ski resort as well as you think you do.

In downtown Ketchum, Idaho, on a sharply cold winter night, fit people in puffy jackets dance to a band playing on a stage planted in the middle of a Wild West street. Clusters of couples peel away for warmth, slipping through vintage doorways into bars and restaurants (some new and hip, others long-established and adorned with taxidermy). The scene is easygoing but lively. Absent are Prada, snootiness, and any apparent Botox.